Flash Cards

Unit 2 Lessons 1 and 2

Question Answer
What can the sand on a beach be part of? A boulder
For how many years can a boulder break down into many smaller pieces? Millions
What is the breakdown of rock material by physical and chemical processes called? Weathering
What are two kinds of weathering? Physical and chemical
What is it called when rocks get smaller and smaller without a change in the composition of the rock? Physical change
What is the process by which rock is broken down into smaller pieces by physical change called? Physical weathering
What are some agents of physical weathering? Temperature changes, pressure changes, plant and animal actions, water, wind, and gravity
When do materials become even more exposed to physical changes? As they break apart
How can changes in temperature cause a rock to break apart? 1. A rise in temperature will cause the rock to expand
2. A decrease in temperature will cause a rock the contract
3. Repeated temperature changes can weaken the structure of a rock, causing the rock to crumble
Even changes in temperature between ____ and ____ temperatures can be significant Day, night
What is the term used that can cause rock to physically break apart and is sometimes known as frost wedging? Ice wedging
How does ice wedging occur? 1. When water collects in cracks in rocks and the temperature drops, the water may freeze
2. Water expands as it freezes to become ice
3. As ice expands, the crack will widen
4. As more water enters the crack, it can expand into and even larger size.
What can cause even the largest of rocks to split apart? A small crack
What is pressure change? 1. Rocks formed under pressure deep within the Earth become exposed at the surface
2. As overlying materials are removed above the rocks, pressure decreases
3. The rock expands, causing the outermost layers of rock to separate from the underlying layers
What is exfoliation? The process by which the outer layers of rock slowly peel away due to pressure changes
When animals dig burrows into the ground which allows more rock to be exposed, what is this called? Animal action
What are some common burrowing animals? Ground squirrels, prairie dogs, ants, and earthworms
How do these animals allow materials to be exposed at the surface? They move soils
What is more likely to occur at the surface than below the surface? Weathering
What is the breaking down and weathering away of rock material by mechanical action of other rock abrasion

Leave a Reply

Your email address will not be published. Required fields are marked *